/// <summary>
/// Validate and persist the current entity when the form closes.
/// Cannot persist an invalid entity, so asks the user whether they
/// want to close form if the current entity is invalid. This is the
/// only place this class performs validation.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void FormClosingHandler(object sender, FormClosingEventArgs e)
{
if (mCurrentEntity != null)
{
if (mCurrentEntity.IsDirty)
{
ErrorList errors = new ErrorList();
SetCurrentFixedValuesAndValidate(errors);
if (errors.MaxSeverity > ErrorSeverity.Warning)
{
// Validation errors may be displayed before this event fires
// in some scenarios (e.g. DataGridView.RowValidating event).
if (ShowErrorsInFormClosing)
{
ErrorDisplayForm.Show(errors);
}
// Ask if want to discard changes.
string msg = string.Format("If you close the form you will lose " +
"edits to the current {0}. Do you wish to close the form?",
DataSource.EntityDisplayName);
DialogResult result = MessageBox.Show(msg, "Close Form", MessageBoxButtons.YesNo);
// NOTE: Empirically, on entry c.Cancel==true if there was a validation
// error in RowValidating, and c.Cancel==false if not. This suggests that
// DataGridView adds its own FormClosing event handler and prevents the
// form from closing if there is a validation error.
e.Cancel = (result != DialogResult.Yes);
}
else
{
// Save without asking.
DataSource.Save(CurrentEntity);
}
}
}
}
/// <summary>
/// Determine if it is okay to change this.DataSource, and if it is okay
/// and the current record has unsaved changed then save that record.
/// Is not okay if the current record is invalid.
/// </summary>
/// <returns></returns>
public bool IsOkayToChangeDataSource(string operation)
{
if (mCurrentEntity != null)
{
if (mCurrentEntity.IsDirty)
{
ErrorList errors = new ErrorList();
SetCurrentFixedValuesAndValidate(errors);
if (errors.MaxSeverity > ErrorSeverity.Warning)
{
ErrorDisplayForm.Show(errors);
// Ask if want to discard changes.
string msg = string.Format("If you {1} you will lose " +
"edits to the current {0}. Do you wish to {1}?",
DataSource.EntityDisplayName, operation);
DialogResult result = MessageBox.Show(msg, "Close Form", MessageBoxButtons.YesNo);
if (result != DialogResult.Yes)
{
return(false);
}
}
else
{
// Save without asking.
DataSource.Save(CurrentEntity);
}
}
}
return(true);
}
/// <summary>
/// Used by subclasses to validate the current entity if there is one,
/// and show errors if any found.
/// </summary>
/// <returns></returns>
public bool CurrentEntityIsValid()
{
EndEdit();
ErrorList errors = new ErrorList();
if (mCurrentEntity != null)
{
SetCurrentFixedValuesAndValidate(errors);
if (errors.MaxSeverity > ErrorSeverity.Warning)
{
ErrorDisplayForm.Show(errors);
return(false);
}
}
return(true);
}
private void RowDeletingHandler(object sender, DataGridViewRowCancelEventArgs e)
{
EndEdit();
ErrorList errors = new ErrorList();
if (CurrentEntity != null && CurrentEntity.IsPersisted)
{
ValidateDeleting(errors);
if (errors.MaxSeverity > ErrorSeverity.Warning)
{
ErrorDisplayForm.Show(errors);
e.Cancel = true;
return;
}
DialogResult dlgRes = MessageBox.Show("Are you sure you want to delete this row?",
"Confirm Delete", MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
if (dlgRes != DialogResult.OK)
{
e.Cancel = true;
return;
}
}
}